The present invention relates to the discovery that the regulatory control elements of the phthalyl amidase gene isolated from Xanthobacter agilis may be used to drive extra-cellular expression of desired proteins in a heterologous host.
Heterologous expression of recombinant proteins generally results in production of non-soluble material that must be extracted from the transformed cell, solubilized with denaturant, and refolded into the proper configuration in order to obtain soluble functional protein. Thus, a method for extra-cellular expression of soluble proteins is desirable because of the ease associated with purification of the secreted proteins and avoidance of the need for cell extraction and protein refolding procedures.